Canvas stretcher

ABSTRACT

A canvas stretcher including a first gripping mechanism, a second gripping mechanism and a tension mechanism. The first gripping mechanism includes a first lower plate, a first upper plate and a first attachment mechanism that interconnects the first lower plate and the first upper plate. The second gripping mechanism includes a second lower plate, a second upper plate and a second attachment mechanism that interconnects the second lower plate and the second upper plate. The tension mechanism includes a lock mechanism, an attachment plate and a belt. A position of the belt with respect to the lock mechanism may be adjusted to vary spacing between the first gripping mechanism and the second gripping mechanism.

REFERENCE TO RELATED APPLICATION

This patent application claims priority to U.S. Design patent application Ser. No. 29/254,981. The details of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates generally to a system and method for stretching canvas. More particularly, the invention relates to a manual canvas stretcher.

BACKGROUND OF THE INVENTION

One popular medium for painting is canvas. When painting, it is desirable for the canvas on which the painting is being done to be evenly stretched. There are various attempts to provide low cost and easy to use mechanisms for stretching canvas.

de Lama et al., U.S. Pat. No. 3,978,905, describes a canvas stretcher frame that includes a frame member and a plurality of clamp members. The clamp members are attached to the frame member in a spaced-apart relationship. The clamp members are adapted to grasp the canvas.

Matheus, U.S. Pat. No. 3,391,635, discloses a screen stretcher for a printing apparatus. The screen stretcher includes a plurality of stretching elements that are mounted to a frame. Each of the stretching elements includes a clamping mechanism and a pneumatically controlled cylinder for adjusting the position of the clamping mechanism.

SUMMARY OF THE INVENTION

An embodiment of the invention is directed to a canvas stretcher that includes a first gripping mechanism, a second gripping mechanism and a tension mechanism. The first gripping mechanism includes a first lower plate, a first upper plate and a first attachment mechanism that interconnects the first lower plate and the first upper plate. The second gripping mechanism includes a second lower plate, a second upper plate and a second attachment mechanism that interconnects the second lower plate and the second upper plate.

The tension mechanism includes a lock mechanism, an attachment plate and a belt. The locking mechanism is attached to at least one of the first lower plate and the first upper plate. The attachment plate is attached to at least one of the second lower plate and the second upper plate. The belt extends between the lock mechanism and the attachment plate to interconnect the first gripping mechanism and the second gripping mechanism. A position of the belt with respect to the lock mechanism may be adjusted to vary spacing between the first gripping mechanism and the second gripping mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a canvas stretcher according to an embodiment of the invention in an assembled configuration.

FIG. 2 is a top view of the canvas stretcher in a partially dissembled configuration.

FIG. 3 is a bottom view of the canvas stretcher.

FIG. 4 is a side view of the canvas stretcher.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is a canvas stretcher, as illustrated at 10 in the figures. The canvas stretcher 10 generally includes a first gripping mechanism 20, a second gripping mechanism 22 and a tension mechanism 24 that interconnects the first gripping mechanism 20 and the second gripping mechanism 22.

A unique feature of the canvas stretcher 10 is that the first gripping mechanism 20 and the second gripping mechanism 22 are linked and pulled together so that a force on one of the gripping mechanisms also causes a force on the other gripping mechanism. This configuration enables the canvas stretched 10 of the present invention to be free-standing and reduces the number of force-generating stretching components used in prior art devices from two to one in the present invention.

To assist in evenly stretching canvas or other material using the canvas stretcher 10, the first gripping mechanism 20 and the second gripping mechanism 22 may be selected with a length that is approximately the same as the length of the canvas or other material that is being stretched. Alternatively, it is possible for the canvas stretcher 10 to be formed with a length that is less than the length of the canvas or other material that is being stretched and to use two or more canvas stretchers 10 adjacent to each other.

The first gripping mechanism 20 and the second gripping mechanism 22 may have a substantially similar configuration that generally includes a lower plate 30 and an upper plate 32. The lower plate 30 and the upper plate 32 may have an approximately equal length and may be substantially flat.

The lower plate 30 and the upper plate 32 may be interconnected with at least one attachment mechanism 40. To facilitate obtaining an approximately equal gripping ability along the length of the first gripping mechanism 20 and the second gripping mechanism 22, there may be a plurality of attachment mechanisms 40 that are oriented in a spaced-apart configuration along the lower plate 30.

In one configuration, the attachment mechanism 40 includes a knob 42 that is attached to a threaded stud (not shown) that extends from the lower plate 30. To enhance the ability to grip the knob 42, the knob 42 may include a textured surface such as at least one extension 44 extending therefrom.

To facilitate gripping the upper plate 32 with the attachment mechanism 40, the upper plate 32 may include at least one slot 46 or aperture formed therein. The at least one slot 46 is oriented on the upper plate 32 to generally correspond with the position of the attachment mechanisms 40 on the lower plate 30.

Using the at least one slot 46 enables the attachment mechanisms 40 to be positioned in a partially engaged position prior to positioning the canvas or other material being stretched and then the upper plate 32 is slid into position over the lower plate 30 by moving the attachment mechanisms 40 to extend into the slots 46. This technique minimizes disturbance of the canvas or other material being stretched to thereby facilitate substantially even stretching of the canvas or other material.

The tension mechanism 24 is adjustable to enable the canvas stretcher 10 to be used in conjunction with canvas or other material having a variety of widths. The tension mechanism 24 may include a lock mechanism 50, an attachment plate 52 and a belt 54.

The lock mechanism 50 may be attached to the lower plate 30 of the first gripping mechanism 20. The lock mechanism 50 allows the belt 54 to be positioned therein. The lock mechanism 50 may be positionable in a locking configuration and a release configuration. When in the locking configuration, the lock mechanism 50 allows the belt 54 to be tightened such as when stretching the canvas or other material. When in the release configuration, the lock mechanism 50 allows the belt 54 to be loosened such as when done using the canvas stretcher 10. The lock mechanism 50 may operate using a ratcheting type system.

In an alternate configuration, the canvas stretcher 10 includes at least two tension mechanisms 24 that are mounted at selected locations along the first gripping mechanism 20 and the second gripping mechanism 22. Using at least two tension mechanisms 24 enhances the ability to evenly stretch the canvas or other material when the canvas or other material has a relatively large width.

The lock mechanism 50 may include a shaft 56, a locking arm 58 and a handle 60. The handle 60 is operably attached to the locking arm 58 to move the locking arm 58 between the locking configuration and the release configuration. The locking arm 58 may be biased to the locking configuration.

The attachment plate 52 may be attached to the lower plate 30 of the second gripping mechanism 22. The attachment plate 52 may have an aperture 62 formed therein that is adapted to receive a hook 64 that is attached to the belt 54 to facilitate interconnecting the lock mechanism 50 and the attachment plate 52 with the belt 54.

In operation, the lower plate 30 of the first gripping mechanism 20 is placed over a first portion of canvas or other material that is to be stretched. The upper plate 32 of the first gripping mechanism 20 is positioned adjacent the lower plate 30 of the first gripping mechanism 20 so that the attachment mechanisms 40 at least partially extend into the associated slots 46. The knobs 42 are then tightened to retain the canvas or other material being stretched in a fixed position with respect to the first gripping mechanism 20.

The process is then repeated to attach a second portion of canvas or other material that is to be stretched to the second gripping mechanism 22. Thereafter, the canvas or other material that is to be stretched is placed over a frame (not shown) so that the first portion and the second portion extend over opposite sides of the frame.

The hook 64 is extended into the aperture 62 to attach the first gripping mechanism 20 to the second gripping mechanism 22 using the belt 54. With the lock mechanism 50 in the locking configuration, the belt 54 is tightened to stretch the canvas or other material over the frame. The stretched canvas or other material is then used such as by painting a portrait thereon. When done using the canvas stretcher 10, the lock mechanism 50 is moved to the release configuration and the belt 54 is loosened.

The hook 64 is detached from the attachment plate 52 and the knobs 42 are loosened to separate the upper plates 32 from the lower plates 30 and thereby detach the first gripping mechanism 20 and the second gripping mechanism 22 from the canvas or other material that was stretched.

It is contemplated that features disclosed in this application, as well as those described in the above applications incorporated by reference, can be mixed and matched to suit particular circumstances. Various other modifications and changes will be apparent to those of ordinary skill. 

1. A canvas stretcher comprising: a first gripping mechanism comprising a first lower plate, a first upper plate and a first attachment mechanism that detachably interconnects the first lower plate and the first upper plate; a second gripping mechanism comprising a second lower plate, a second upper plate and a second attachment mechanism that detachably interconnects the second lower plate and the second upper plate; and a tension mechanism comprising a lock mechanism, an attachment plate and a belt, wherein the locking mechanism is attached to at least one of the first lower plate and the first upper plate, wherein the attachment plate is attached to at least one of the second lower plate and the second upper plate, wherein the belt extends between the lock mechanism and the attachment plate to interconnect the first gripping mechanism and the second gripping mechanism, and wherein a position of the belt with respect to the lock mechanism may be adjusted to vary spacing between the first gripping mechanism and the second gripping mechanism.
 2. The canvas stretcher of claim 1, wherein the first upper plate has a length that is approximately the same as a length of the first lower plate and wherein the second upper plate has a length that is approximately the same as a length of the second lower plate.
 3. The canvas stretcher of claim 1, wherein the first attachment mechanism further comprises a first knob threadably attached to the first lower plate and wherein the second attachment mechanism further comprises a second knob threadably attached to the second lower plate.
 4. The canvas stretcher of claim 1, wherein the first upper plate has at least one first slot or aperture formed therein, wherein the first slot or aperture is adapted to receive one of the first attachment mechanisms, wherein the second upper plate has at least second one slot or aperture formed therein, and wherein each slot or aperture is adapted to receive one of the second attachment mechanisms.
 5. The canvas stretcher of claim 1, wherein the lock mechanism comprises a shaft, a locking arm and a handle, wherein the handle is operably attached to the locking arm to move the locking arm between a locking configuration and a release configuration.
 6. The canvas stretcher of claim 5, wherein the lock mechanism has a ratchet configuration.
 7. The canvas stretcher of claim 5, wherein the locking arm is biased to the locking configuration.
 8. The canvas stretcher of claim 1, wherein a hook is operably attached to the belt, wherein the attachment plate has an aperture formed therein, and wherein the aperture is adapted to receive the hook.
 9. A method of stretching canvas having a first canvas portion and a second canvas portion, the method comprising: placing the first canvas portion between a first lower plate and a first upper plate of a first gripping mechanism, wherein at least one of the first lower plate and the first upper plate has a lock mechanism attached thereto; attaching the first lower plate to the first upper plate with a first attachment mechanism; placing the second canvas portion between a second lower plate and a second upper plate of a second gripping mechanism, wherein at least one of the second lower plate and the second upper plate has an attachment plate attached thereto; attaching the second lower plate to the second upper plate with a second attachment mechanism; positioning the canvas so that the first canvas portion and the second canvas portions extend over opposite edges of a frame; attaching a first end of a belt to the attachment plate; and operably attaching a second end of the belt to the lock mechanism, wherein a position of the belt with respect to the lock mechanism may be adjusted to vary spacing between the first gripping mechanism and the second gripping mechanism.
 10. The method of claim 9, and further comprising forming the first upper plate with a length that is approximately the same as a length of the first lower plate and forming the second upper plate with a length that is approximately the same as a length of the second lower plate.
 11. The method of claim 9, wherein the first attachment mechanism further comprises a first knob threadably attached to the first lower plate and wherein the second attachment mechanism further comprises a second knob threadably attached to the second lower plate.
 12. The method of claim 9, wherein the lock mechanism is operable in either a locking configuration and a release configuration, wherein the locking mechanism is biased in the locking configuration and wherein the lock mechanism comprises a shaft, a locking arm and a handle.
 13. The method of claim 12, wherein the lock mechanism has a ratchet configuration.
 14. The method of claim 9, and further comprising: forming at least one first slot or aperture in the first upper plate, wherein the first slot or aperture is adapted to receive one of the first attachment mechanisms; and forming at least second one slot or aperture in the second upper plate, wherein each slot or aperture is adapted to receive one of the second attachment mechanisms.
 15. The method of claim 9, wherein a hook is operably attached to the belt, wherein the attachment plate has an aperture formed therein, and wherein the belt is attached to the attachment plate by extending the hook at least partially into the aperture.
 16. The method of claim 9, wherein the varying a spacing between the first gripping mechanism and the second gripping mechanism is accomplished without attachment to components external to the canvas stretcher.
 17. A canvas stretcher comprising: a first gripping mechanism comprising a first lower plate, a first upper plate and a first attachment mechanism, wherein the first upper plate has at least one first slot or aperture formed therein, wherein the first attachment mechanism comprises a first knob threadably attached to the first lower plate, and wherein the first slot or aperture is adapted to receive one of the first attachment mechanisms; a second gripping mechanism comprising a second lower plate, a second upper plate and a second attachment mechanism, wherein the second upper plate has at least one second slot or aperture formed therein, wherein the second attachment mechanism comprises a second knob threadably attached to the second lower plate, and wherein the second slot or aperture is adapted to receive one of the second attachment mechanisms; and a tension mechanism comprising a lock mechanism, an attachment plate and a belt, wherein the locking mechanism is attached to at least one of the first lower plate and the first upper plate, wherein the attachment plate is attached to at least one of the second lower plate and the second upper plate, wherein the belt extends between the lock mechanism and the attachment plate to interconnect the first gripping mechanism and the second gripping mechanism, and wherein a position of the belt with respect to the lock mechanism may be adjusted to vary spacing between the first gripping mechanism and the second gripping mechanism.
 18. The canvas stretcher of claim 17, wherein the first upper plate has a length that is approximately the same as a length of the first lower plate and wherein the second upper plate has a length that is approximately the same as a length of the second lower plate.
 19. The canvas stretcher of claim 17, wherein the lock mechanism comprises a shaft, a locking arm and a handle, wherein the handle is operably attached to the locking arm to move the locking arm between a locking configuration and a release configuration.
 20. The canvas stretcher of claim 17, wherein the locking arm is biased to the locking configuration.
 21. The canvas stretcher of claim 17, wherein a hook is operably attached to the belt, wherein the attachment plate has an aperture formed therein, and wherein the aperture is adapted to receive the hook. 